Recently, image compression standards such as JPEG2000/JPIP (JPEG 2000 Interactive Protocol) have been introduced to meet a demanding engineering goal: to enable very large images (i.e. gigapixels in size) to be delivered incrementally or selectively from a server to a client over a low-bandwidth communication channel. (See David Taubman's implementation of Kakadu at www.kakadusoftware.com). When such images are being viewed at full resolution, only a limited region of each image can fit on a client's graphical display at any given time. The new standards are geared toward selectively accessing such regions and sending across the communication channel only data relevant to the region. If this “region of interest” or ROI changes continuously, then a continuous dialogue between a client and server over a low-bandwidth channel can continue to keep the client's representation of the area inside the ROI accurate.
However, existing approaches generally require the transmission of substantial amounts of data to significantly shift the location of the region of interest, thus limiting the speed at which such shifts may be implemented. Moreover, existing approaches generally depend on sequential access to a linear string of text, thereby imposing a significant burden on text navigation when a client seeks to significantly change the location of the region of interest. Accordingly, an improved method for transmitting data from a server to a client is needed.